Tipping a golf shaft is a way of fine tuning the stiffness of a shaft. It increases the stiffness of a shaft to exactly match the desired shaft flex when the natural variation in shafts does not result in the correct stiffness.
Tipping a golf shaft simply means removing or cutting the tip section of the shaft up to 20mm. Removing material at the tip end will increase the overall stiffness of the shaft. The shaft is then set to the correct length by cutting the butt section of the shaft.